In a vehicle equipped with fuel cells, a motor is driven with electric power generated by the fuel cells, and the driving power of the motor is used to rotate an axle with wheels and drive the vehicle. One proposed structure of such a vehicle has exhaust piping with an outlet to discharge the exhaust gas from the fuel cells to the outside of the vehicle. This outlet is generally located at an underfloor position in a rear portion of the vehicle main body, like the conventional vehicle driven with the output power of an internal combustion engine (see, for example, Japanese Patent Laid-Open No. 2002-289237). This arrangement of the outlet enables the exhaust gas from the fuel cells and water produced by power generation or by electrochemical reaction of hydrogen with oxygen (hereafter the exhaust gas and the produced water may collectively be referred to as ‘exhaust fluid’) to be discharged directly onto the road surface. One known gas discharge structure for vehicle-installed fuel cells is disclosed in, for example, Japanese Patent Laid-Open No. 2003-219512.
In the prior art structure disclosed in Japanese Patent Laid-Open No. 2002-289237, however, during drive of the vehicle equipped with the fuel cells on the water-covered road, the outlet may be blocked by the water, soil, sand, and other equivalent substances present on the road surface. Such blockage of the outlet may interfere with the smooth discharge of the exhaust gas and the produced water and stop power generation by the fuel cells to eventually prevent further run of the vehicle. The water, soil, sand, and other equivalent substances flowed into the outlet may run through the piping to reach the inside of the fuel cells and cause malfunction of the fuel cells.
This problem is not characteristic of the vehicle equipped with fuel cells but is commonly found in various moving bodies equipped with fuel cells and configured to be driven on the road surface with electric power generated by the fuel cells as the driving power source. Typical examples of such moving bodies include air craft and boats and ships, in addition to the vehicles.